A computing device may be configured to transmit communications to, and receive communications from, other computing devices. These communications may include data or any information that is transmitted between devices either wirelessly or via a wired connection. Communications that are public or otherwise do not include sensitive information may be unsecured. Communications that are intended to be private to two or more devices may be encrypted such that the information contained therein is not readily available to unauthorized devices.
In some examples, communications between an external device (e.g., a medical device programmer or data acquisition device) and an implantable medical device (e.g., a pacemaker, a defibrillator, a neurostimulator, a sensor, or a drug pump) may be encrypted to secure sensitive information such as collected patient data or programming instructions that at least partially define the operation of an implantable medical device. Secure communication involving medical devices may involve an encryption scheme known to both the external device and the implantable medical device. For example, both the external device and the implantable medical device may utilize a stored encryption key to encrypt and/or decrypt some or all information transmitted between the devices.
Implantable medical devices including those that are positioned on the exterior of a body of a patient as well as those that are positioned subcutaneously or deeper typically utilize an on-board battery that allows the patient to be untethered to a power source. The patient maintains mobility while the implantable medical device performs a particular medical task by operating on power from the battery. For instance, the implantable medical device may provide electrical stimulation therapy for neurological or cardiac conditions, may provide drug delivery for various conditions such as pain management, and/or may provide physiological monitoring.
While the on-board battery may power the medical device for a relatively long period of time, the on-board battery will eventually be depleted. Prior to rechargeable medical systems, the implantable medical device would be replaced once the battery became depleted. With rechargeable medical systems, an external device (i.e., a wireless charger) provides recharge energy over a proximity coupling, which is typically inductive, to the implantable medical device. This recharge energy restores the on-board battery to a satisfactory level for continued operation of the medical device.